The audio file in FF X/X-2 HD Remaster is merely there to expand the universe.
After the recently released Final Fantasy X/X-2 HD Remaster was discovered to have a brief audio episode, fans started to speculate that Square put it in to set the groundwork for a third game in the series. This isn’t the case, however, according to Shinji Hashimoto.
Upon being asked if they were announcing a third game, Mr. Hashimoto stated, “That’s not really our intentions with including the audio episode. Since we’re revisiting Final Fantasy X and X-2, which were released about 10 years ago, the series’ scenario writer Kazushige Nojima and character designer Tetsuya Nomura had a discussion and thought that the HD Remaster release would be a good opportunity for them to include this additional story episode and expand upon the universe a little further. But the audio episode’s inclusion wasn’t because we have any plans to develop a Final Fantasy X-3.”
Mr. Hashimoto was also asked about a possible Final Fantasy XII HD Remaster since Kitase had expressed interest in creating it providing that the X/X-2 Remaster sold well. He stated that if enough fans ask for it the company would consider it, but there are currently no plans.
Finally, our friends at SG Café uploaded a video showing Mr. Hashimoto’s answer to if Square would be remaking Final Fantasy VII, a game fans have been wanting redone for years: